Coarctation of the Aorta

Coarctation of the Aorta

Description, Managements, and Sequelae

To understand the anatomy of the arch

Terminology

Types of surgical repairs and outcomes

Catheterization interventions and outcomes

Longterm sequelae

ObjectivesObjectives

ridge-like thickening of the aortic media

ledge-like posterolateral wall

eccentrically narrows aortic lumen

intimal thickening contributes later

What is it?What is it?

Aortic arch - definitionsAortic arch - definitions

40%

100%

60% 50%

Preductal“Infantile” Coarctation

=disorder with diffuse narrowing(hypoplasia) and constrictive zone between the left subclavian artery and ductus arteriosus

Postductal“Adult” Coarctation

=disorder with short segment narrowing just beyond insertion of ligamentum arteriosum, no intracardiac defect, and degenerative aortic wall changes

Paraductal or Juxtaductal

Abdominal aorta

CongenitalCongenital

PreductalPreductal

PostductalPostductal

ParaductalParaductal

AcquiredTakayasu’s arteritis

Post surgical ie dTGA switch

Pseudocoarctationkinking/buckling of aorta with little or no obstruction to blood flow

no abnormality of the intima media

Coarctation (2)Coarctation (2)

What else? -Associated lesions

What else? -Associated lesions

VSD

Aortic valve - bicuspid stenosis - valvular, sub-valvular

Mitral valve - supravalvular ring, dysplastic leaflets, parachute

Berry aneurysms of Circle of Willis

Anomalous RSCA

Coronary artery anomalies

Why? -Etiology- theoriesWhy? -Etiology- theories

Anomalous fibroductal tissue surrounding aorta

contraction and fibrosis as ductus closes to pull shelf toward contralateral wall

abnormal fetal hemodynamics

isthmal flow <10% in fetal life

if reduced LV output --> decr isthmal flow --> leading to under development of segment

Extent of Ductal tissue in coarctationExtent of Ductal tissue in coarctation

Why? -GeneticsWhy? -Genetics

Sporadic (1/2323 live births)left heart lesions in twins, siblings, first degree rel’s

Male > Female : discrete thoracic coarctations

Turner’s syndrome (XO) - 15-35%

Adams-Oliver syndrome

Clinical signs - When?Clinical signs - When?Infancy

Congestive heart failure - as ductus closes; cyanosis, shock,

Poor Femoral pulsatility

Differential saturations - ductus open

Post InfancyHypertension - upper extremity; systolic, diastolic

Brachio-femoral delay; strong UE/carotid pulses

Murmur of coarctation & bruits from collateral vessels

Corkscrew appearance to retinal arteries

ECGECGInfancy

RBBB or RVH

Uncommon to have LVH +/- strain

Post InfancyNormal

RBBB, LVH +/- strain, exercise testing may unmask strain

CXRCXRInfancy

Venous congestion

Increased PVM’s

Post InfancyMild Cardiomegaly with prominent LV contour

Dilated Ascending aorta and aortic knob

3 sign (E sign on Ba swallow)

Rib notching

Imaging aortic arch(1)Imaging aortic arch(1)Echocardiography 2D images

Antenatal U/S

Postnatal: SSN & high left parasternal views

- hypoplasia, interruption, arch sidedness, brachiocephalic vessels

Aortic, Mitral valves, EFE, VSD, LVH, function

Echo DopplerAbdominal aorta pulsatility

Continuous antegrade flow across DSAO (Shark’s tooth appearance)

Double flow envelopes

Imaging aortic arch(2)Imaging aortic arch(2)CT scan

Advantages : speed, resolution, availability, larger child

Disadvantages : ionizing radiation (neonates)

MRI/MRAAdv : resolution, no ionizing radiation, larger child

Dis : long acquisition times, availability, expertise, anesthesia risks

Natural historyNatural historyNo intervention

If survived beyond 1 year: 75% mortality before 46yr

CHF (26%), aortic rupture (21%), endocarditis (18%), intracranial hemorrhage (12%)

Aortic rupture or dissection

thoracic aorta - intrinsic abnormality of media, hypertension, infection

75% ascending aorta

obstetrical risk dissecting aneurysm (last trimester, labour, post)

spontaneous rupture of distal aorta - younger patients

Medical therapyMedical therapy

InfancyProstaglandin E1- opens ductus, reverses hypoperfusion

Post InfancyHypertension- pre/post repair

Surgical repairSurgical repairDependant on anatomy of arch

End to End anastomosis

Extended End to End anastomosis

Subclavian flap aortoplasty

Synthetic patch aortoplasty

Graft aortoplasty

End to End anastomosisEnd to End anastomosis

Limitations of End to EndLimitations of End to End

High rate of recoarctation : 20-86%esp <1yr age

d/t: silk vs monofilament

inadequate resection ductal tissue

lack of growth circumferential suture line

lack of growth hypoplastic transverse arch

Extended End to EndExtended End to End

Extended End to End resultsExtended End to End resultsAuthor Age Year Patients Operative

Mortality %Recoarctatio

n %

Lansman etal 6mo 1986 17 6 12

Vouhe 3mo 1988 80 26 10

Zannini 3mo 1993 21 19 23

Van Heurn 3mo 1994 77 6 11

Kappetein 3yr 1994 26 15 0

Conte <1mo 1995 307 7 9

van Son <1mo 1997 25 0 4

Backer <6mo 1997 55 2 4

TOTALS 608 10 8

Subclavian flap aortoplastySubclavian flap aortoplasty

SCFA resultsSCFA resultsAuthor Age Year Patients Mortality % Recoarctation

%

Metzdorff etal <2mo 1985 60 18 17

Ziemer <1mo 1986 70 11.4 15

Ehrhardt & Walker <1mo 1989 45 31 23

Milliken <1mo 1990 123 9 16

Van Heurn <3mo 1994 15 7 42

Quaegebeur <1mo 1994 112 8 12

Allen <3mo 2000 53 0 4

Jahangiri <3mo 2000 185 3 6

TOTALS 663 9 12

End-End v.s Subclavian flapEnd-End v.s Subclavian flapAge Mortality Freedom

ReintervenSurvival

5yr

Van Son et al. n=70 (1989)

3d-5.2mon Grp1n=25 100%

SCFA n=19 11% 87% Grp2n=19 73%

End-End n=51 24% 95% Grp3n=26 28%

Recurrentcoarct Survival 10yr

Rubay et aln=146 (1992)

Grp1n=65 100%

SCFA n=39 15% no diff Grp2n=49 94%

End-End n=107 18% Grp3n=32 62%

Patch aortoplastyPatch aortoplasty

Results of Patch AortoplastyResults of Patch AortoplastyAuthor Age Year Patients Operative

MortalityRecoarctatio

n Aneurysm Patch

Yee et al <1yr 1984 100 0 10(12%) 0 PTFE

Clarkson et al >15yr 1985 38 NS 6(16%) 5(13%) Dacron

Hehrlein et al 2d-64yr 1986 317 16(5%) 4(1.3%) 18(6%) Dacron

Del Nido et al 3d-32yr 1986 63 1(2%) 8(13%) 3(5%) Dacron

Ungerleider NS 1991 54 0 2(5%) 0 PTFE

Backer et al 5.1yr mean 1994 125 4(3%) 10(8%) 0 PTFE

TOTALS 697 21(3%) 40(6%) 25(4%)

Graft aortoplastyGraft aortoplasty

Intra and post-operative complications

Intra and post-operative complications

recurrent laryngeal nerve injury

phrenic nerve injury

predisposition to bleeding-collateral/suture

chylothorax

postcoarctectomy syndrome (mesenteric arteritis)

paradoxical hypertension

spinal cord ischemia

Paradoxical postop hypertension

Paradoxical postop hypertension

1) Immediate - subsides in 24 hrd/t release of stretch on carotid baroreceptors

incr’d NE levels from incr’d sympathetic activity

until baroreceptors reset to lower level

approx 1/2 ptts

2) Second phase - w/in 48-72hr1/3 who have 1st phase

incr’d Renin and Angiotensin

more pronounced in diastole

?abnormal adaptation to ensure LE blood flow

Spinal cord ischemiaSpinal cord ischemia

Paralysis of lower extremitiesrare - <0.5%

Risks: prolonged aortic X-clamping

reduced arterial collateral vessels

sacrifice intercostal vessels

hyperthermia

Modified History -Outcomes

Modified History -Outcomes

Recoarctation - 3% if surgery at >3yr age

Survival - 62% at 30yr if surgery at <14 yrs

Hypertension post repair: 48% at 10yr, 55% at 20yr, 60% at 30yr, 74% at 40yr

Exercise induced hypertension- vessel compliance

LV hypertrophy

Accelerated CAD

Aortic aneurysm and dissection

Aortic aneurysmsAortic aneurysmsTrue aneurysms

incr’d with use of prosthetic material - Bergdahl JTCS 1980

opposite wall of patch (pulse wave transmission)

Dacron > PTFE

6-13% incidence

38% incidence in adult repairs by 14yrs post - PM Clarkson, AMJ 1985

Alternatives to Surgical repair/palliation

Alternatives to Surgical repair/palliation

• Balloon angioplasty

• +/- Stent placement

Balloon angioplastyBalloon angioplastyRecurrent vs Native Coarctation dilatation

Tearing the intimal and medial layers

Sohn et al. : IVUS delineation of intimal tear/flap/dissection in majority of cases

Underlying histological medial changes similar to cystic medial necrosis

Risk of rupture, dissection, late aneurysm

Restenosis from neofibroelastic proliferation

defined as gradient >20mmHg

Guidelines for balloon angioplasty

Guidelines for balloon angioplasty

Balloon size not to exceed 2mm of aortic diameter proximal to coarctation

may be 2-3 times diameter of coarctation

Neonates and young infants have higher restenosis

likely d/t persistent active ductal tissue

Significant tears can partly or completely heal

Native vs recurrent coarctation - acute results

Native vs recurrent coarctation - acute results

BW McCrindle, et al (VACA registry)970 procedures in 907 patients at 25 institutions

Age: 2 days - 63yr

Equivalent acute results

Complications: slightly more intimal tears or flaps in native coarctation

Suboptimal outcome:

older age, higher preangioplasty systolic gradient, recurrent obstruction,

Stenting vs Balloon angioplasty(1)

Stenting vs Balloon angioplasty(1)

Recoarctation following balloon• angioplasty (18-31% native)

elastic recoil

long segment stenosis

slightly larger dilated diameter with stents

Aneurysm formation and aortic ruptureimmediate and late complication

occurs with Both techniques

Stenting vs Balloon angioplasty(2)

Stenting vs Balloon angioplasty(2)

Stents - idealunlimited dilatable diameter

no length shortening

high radial strength

flexibility

low profile

non-sharp edges

wide struts for collateral vessels

Inherent limitation of stents

Stent placement guidelinesStent placement guidelinesSimilar balloon sizing for angioplasty

lesser of the proximal transverse arch or descending aorta at the level of the diaphragm

flaring of the ends of stent - discretion

NB. acheiving perfect result at time of implantation not necessary

if sig residual gradient - wait 6 months for repeat dilatation

Aspirin for 1 year

Neointimal growth causes mild restenosis

Aortic rupture post stent placement

Aortic rupture post stent placement

Aortic rupture post stent placement

Aortic rupture post stent placement

Aortic rupture post stent placement

-partial intimo-medial rupture

Aortic rupture post stent placement

-partial intimo-medial rupture

Stent cautionsStent cautions

if dilation diameter >3 times coarctation, consider covered stent

adult patient may have different histological changes --> ? more susceptible for dissection

use other imaging modalities to measure coarctation site, proximal aorta, and descending aorta (ie MRI, IVUS, CT)

Age guidelines?Age guidelines?Native and recurrent coarctation

Less than 6 months age with discrete coarct

Balloon angioplasty palliation for heart failure

Less than 6 years and > 6months

Balloon angioplasty +/- stent (palliative)

higher endoproliferative restenosis rate with small diameter stents

Older than 6 year (>= 12mm stent)

Stent placement

Adolescent and Adult patient

Covered stent placement

• JS de Lezo et al. Ped Card, 2005

SummarySummaryWhat is coarctation of the aorta?

What are the surgical and catheterization options?

What are the outcomes and sequelae for both?

What is the optimal age for balloon +/- stent dilatation of coarctation?

QuestionsQuestions

References(1)References(1)A Garson, et al. The Science and Practice of Pediatric Cardiology, 2nd ed., 1998: Chpt 58.

RM Freedom. The Natural and Modified History of Congenital Heart Disease, 2004.

A Smith & R McKay. A Practical Atlas of Congenital Heart Disease. Springer, 2004.

C Mavroudis, CL Backer. Pediatric Cardiac Surgery, 3rd ed, 2003.

BW McCrindle, et al (VACA registry). Acute results of balloon angioplasty of Native coarctation versus Recurrent aortic obstruction are Equivalent. JACC 28(7): 1810-7, 1996.

C Varma, et al. Aortic Dissection after stent dilataion for Coarctation of the Aorta: A Case report and Literature review. Cath Cardio Interv 59: 528-35, 2003.

References (2)References (2)

CAC Pedra, et al. Stenting vs. Balloon Angioplasty for Discrete Unoperated Coarctation of the Aorta in Adolescents and Adults. Cath Cardio Interv 64:495-506, 2005.

MR Ebeid. Balloon expandable stents for coarctation of the aorta: review of current status and technical considerations. Imag Paed Cardiol 15:25-41, 2003.

J Suarez de Lezo, et al. Percutaneous Interentions on Severe Coarctation of the Aorta: A 21 year experience. Ped Card 26:176-89, 2005.